915 research outputs found

    Integrating dark and light biohydrogen production strategies: towards the hydrogen economy

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    Biological methods of hydrogen production are preferable to chemical methods because of the possibility to use sunlight, CO2 and organic wastes as substrates for environmentally benign conversions, under moderate conditions. By combining different microorganisms with different capabilities, the individual strengths of each may be exploited and their weaknesses overcome. Mechanisms of bio-hydrogen production are described and strategies for their integration are discussed. Dual systems can be\ud divided broadly into wholly light-driven systems (with microalgae/cyanobacteria as the 1st stage) and partially light-driven systems (with a dark, fermentative initial reaction). Review and evaluation of published data suggests that the latter type of system holds greater promise for industrial application. This is because the calculated land area required for a wholly light-driven dual system would be too large for either centralised (macro-) or decentralised(micro-) energy generation. The potential contribution to the hydrogen economy of partially light-driven dual systems is overviewed alongside that of other biofuels such as bio-methane and bio-ethanol

    Late Modern War and the <em>Geos</em>

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    This article works towards an ontology of war centred on the life of the planet, or geos. Noting a disciplinary tendency to focus on the makers of war, we ask what if our analyses of war begin not with the technologies of killing but with the life that is targeted? Our response proceeds in four sections. We first identify a “militarised ontology” of war that forms through the ways that militaries figure violence as spatially and temporally “precise” and thus distinct from longer-term environmental effects. We then argue that these ontological bounds persist also in critical scholarship on war. Writing against such ontological contingencies, we learn from feminist IR to set out a theoretical path for knowing war on different terms, from the perspective of the geos. From here our main contribution forms: attending to war ecologies and non/human health, war appears in a form that critically contrasts with a large part of current work in IR, it is no longer a primarily accelerated, aerial or remote activity but rather an enduring, terranean, and proximate intervention in the environment and the life it sustains. We close with explication of the significance of geos-centred study of war in IR and beyond

    Wastewater irrigation and health: assessing and mitigating risk in low-income countries

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    Wastewater irrigation / Public health / Health hazards / Risk assessment / Epidemiology / Sewage sludge / Excreta / Diseases / Vegetables / Leaf vegetables / Economic impact / Wastewater treatment / Irrigation methods / Developing countries

    Polyhydroxybutyrate accumulation by a Serratia sp

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    A strain of Serratia sp. showed intracellular electron-transparent inclusion bodies when incubated in the presence of citrate and glycerol 2-phosphate without nitrogen source following pregrowth under carbon-limitation in continuous culture. About 1.3 mmol citrate were consumed per 450 mg\ud biomass, giving a calculated yield of maximally 55% of stored material per g of biomass dry wt. The inclusion bodies were stained with Sudan Black and Nile Red (NR), suggesting a lipid material, which was confirmed as polyhydroxybutyrate (PHB) by analysis of molecular fragments by GC and by FTIR spectroscopy of isolated bio-PHB in comparison with reference material. Multi-parameter flow cytometry in conjunction with NR fluorescence, and electron microscopy, showed that not all cells contained heavy PHB bodies, suggesting the potential for increasing\ud the overall yield. The economic attractiveness is\ud enhanced by the co-production of nanoscale hydroxyapatite\ud (HA), a possible high-value precursor for bone replacement materials

    Effect of prolonged space flight on cardiac function and dimensions

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    Echocardiographic studies were performed preflight 5 days before launch and on recovery day and 1, 2, 4, 11, 31 and 68 days postflight. From these echocardiograms measurements were made. From these primary measurements, left ventricular end-diastolic volume, end-systolic volume, stroke volume, and mass were derived using the accepted assumptions. Findings in the Scientist Pilot and Pilot resemble those seen in trained distance runners. Wall thickness measurements were normal in all three crewmembers preflight. Postflight basal studies were unchanged in the Commander on recovery day through 68 days postflight in both the Scientist Pilot and Pilot, however, the left ventricular end-diastolic volume, stroke volume, and mass were decreased slightly. Left ventricular function curves were constructed for the Commander and Pilot by plotting stroke volume versus end-diastolic volume. In both astronauts, preflight and postflight data fell on the same straight line demonstrating that no deterioration in cardiac function had occurred. These data indicate that the cardiovascular system adapts well to prolonged weightlessness and suggest that alterations in cardiac dimensions and function are unlikely to limit man's future in space

    Intranasal administration of RSV antigen-expressing MCMV elicits robust tissue-resident effector and effector memory CD8+ T cells in the lung

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    Cytomegalovirus vectors are promising delivery vehicles for vaccine strategies that aim to elicit effector CD8+ T cells. To determine how the route of immunization affects CD8+ T cell responses in the lungs of mice vaccinated with a murine cytomegalovirus vector expressing the respiratory syncytial virus matrix (M) protein, we infected CB6F1 mice via the intranasal or intraperitoneal route and evaluated the M-specific CD8+ T cell response at early and late time points. We found that intranasal vaccination generated robust and durable tissue-resident effector and effector memory CD8+ T cell populations that were undetectable after intraperitoneal vaccination. The generation of these antigen-experienced cells by intranasal vaccination resulted in earlier T cell responses, interferon gamma secretion, and viral clearance after respiratory syncytial virus challenge. Collectively, these findings validate a novel approach to vaccination that emphasizes the route of delivery as a key determinant of immune priming at the site of vulnerability

    Using the National Early Warning Score (NEWS) outside acute hospital settings: A qualitative study of staff experiences in the West of England

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    © 2018 Author(s) (or their employer(s)). Objectives Early warning scores were developed to improve recognition of clinical deterioration in acute hospital settings. In England, the National Early Warning Score (NEWS) is increasingly being recommended at a national level for use outside such settings. In 2015, the West of England Academic Health Science Network supported the roll-out of NEWS across a range of non-acute-hospital healthcare sectors. Research on the use of NEWS outside acute hospitals is limited. The objective of this study was to explore staff experiences of using NEWS in these new settings. Design Thematic analysis of qualitative semi-structured interviews with purposefully sampled healthcare staff. Setting West of England healthcare settings where NEWS was being used outside acute hospitals - primary care, ambulance, referral management, community and mental health services. Participants Twenty-five healthcare staff interviewed from primary care (9), ambulance (3), referral management/acute interface (5), community (4) and mental health services (3), and service commissioning (1). Results Participants reported that NEWS could support clinical decision-making around escalation of care, and provide a clear means of communicating clinical acuity between clinicians and across different healthcare organisations. Challenges with implementing NEWS varied - in primary care, clinicians had to select patients for NEWS and adopt different methods of clinical assessment, whereas for paramedics it fitted well with usual clinical practice and was used for all patients. In community services and mental health, modifications were 'needed' to make the tool relevant to some patient populations. Conclusions This study demonstrated that while NEWS can work for staff outside acute hospital settings, the potential for routine clinical practice to accommodate NEWS in such settings varied. A tailored approach to implementation in different settings, incorporating guidance supported by further research on the use of NEWS with specific patient groups in community settings, may be beneficial, and enhance staff confidence in the tool

    Re-imagining the futures of geographical thought and praxis

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    The question of geography\u27s future has recurred throughout the history of geographical thought, and responses to it often presume a linear trajectory from the past and present to a possible future. Yet one of the major contributions that geographers have made to understanding spatio-temporality is reconceiving both space and time as plural, fluid, and co-constituted through multiple space–time trajectories simultaneously. Amidst the ongoing crises of the present, this article opens the current special issue with a call to pluralize geography\u27s futures by diversifying the voices speaking in the name of ‘geography’ and broadening the horizon of possibilities for the futures of geographical thought and praxis. We have assembled the contributions in this collection with the aim of raising important theoretical, methodological, and empirical questions about how geography\u27s past and present shape the conditions of possibility for its potential futures. In doing so, we seek to demonstrate how the worlding of geography\u27s futures is fundamentally a matter of transforming its disciplinary reproduction in the here-and-now
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